STMicroelectronics L6920DTR

Overview

L6920DTR from STMicroelectronics is a high-efficiency synchronous step-up DC/DC converter designed for single-to-three-cell battery systems. It operates from 0.6V input, starts up at 1V, delivers fixed 3.3V/5V or adjustable 2–5.2V output, features 120mΩ internal N-channel switch and integrated low-battery detection, and is used in portable digital cameras and GPS receivers.

For engineers reviewing the L6920DTR datasheet, L6920DTR pinout, L6920DTR application, or L6920DTR equivalent, key selection criteria include startup voltage (1V), quiescent current (9–18µA), shutdown current (<1µA), synchronous rectification architecture, and TSSOP8 package compatibility with space-constrained handheld designs.

Technical Context

The L6920DTR uses variable-frequency PFM control with maximum on-time (5µs) and minimum off-time (1µs) regulation to maintain efficiency across light-to-heavy loads. Its current-mode architecture enforces 1A peak inductor current limiting and zero-crossing detection to manage energy transfer during discontinuous conduction mode.

Internal circuitry includes a 1.23V reference (±2.5% over temperature), open-drain LBO output with 1.23V threshold and 1.3% hysteresis, reverse-battery protection that limits reverse current to ≤2µA at −4V, and an internal charge pump enabling low-R_DS(on) gate drive for the N-channel main switch.

Key Specifications

Pinout & Package

TSSOP8 package (4.4mm body width, 0.65mm pitch) with exposed thermal pad not electrically connected; JEDEC MO-153-AA compliant; max junction temperature 150°C; thermal resistance 250°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-up converter applications.

Compared with TPS61022DRCT and MAX17065ETA+, the L6920DTR offers superior ultra-low-input-voltage operation (0.6V), lowest quiescent current in its class, and smallest TSSOP8 footprint-making it optimal for cost-sensitive, space-limited, single-cell battery applications where efficiency at microamp loads is critical.

Availability

L6920DTR is available at Aetrix Electronics and suitable for digital cameras, GPS receivers, PDAs, and cellular handsets requiring stable component supply across long production lifecycles and varying battery chemistries.

Supply support for L6920DTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensing solutions for automotive, industrial, and consumer markets.

The L6920 belongs to ST's low-voltage DC/DC converter product line, engineered specifically for high-efficiency power conversion in portable battery-powered equipment operating down to 0.6V input.

FAQ

What is the minimum input voltage at which L6920DTR sustains regulation?

The L6920DTR maintains regulated output down to 0.6V input across temperature and load conditions, verified per Table 4 Absolute Maximum Ratings and Figure 5 startup curves. This allows full utilization of NiMH and Li-ion cells beyond typical 1.0V cutoff points, extending usable battery capacity by up to 15% in single-cell systems.

How does the L6920DTR implement reverse battery protection?

Reverse battery protection is achieved through an internal MOSFET-based blocking circuit that limits reverse current to ≤2µA at −4V input, as specified in Table 4 Electrical Characteristics. No external components are needed, and the protection remains active in both operating and shutdown modes, preventing damage during incorrect battery insertion.

Can the L6920DTR generate 5V output from a 1.5V alkaline cell?

Yes-the L6920DTR starts up at 1V and regulates 5V output from 1.5V input, confirmed by Figure 5 (startup voltage vs. output current) and Table 4 (V_IN min = 0.6V). At 1.5V input and 50mA load, typical efficiency exceeds 82% (Figure 4), making it viable for multi-cell alkaline applications where voltage drops below 2V during discharge.

Is an external diode required when using the L6920DTR in synchronous mode?

No external diode is required. The L6920DTR integrates a synchronous P-channel rectifier switch (R_ON = 120–250mΩ) that replaces the traditional Schottky diode, reducing forward voltage drop by ~300mV and eliminating associated power loss and thermal stress in the application circuit.